I think there are a few possibilities. The first one is that Red-Reo hasn't been calibrated for the hive yet. The second is that they were so thoroughly corrupted that they couldn't be revived. The third is that the hive mind doesn't really view them as individuals in the same way that the rest of the Tough's did. They might just be extensions of itself, so just popping out a few more and giving them shards of its personality are all that are necessary and it doesn't care if those exact ones come back. The last one is that the revival process does work for the hive, and that it's currently growing them their new bodies and for some reason Tagon either doesn't know about this or thinks the fact that even one iteration got killed is worth the home visit, which would fit with his philosophy of how the revival process works.

Personally I like the third or fourth possibilities as the hive mind doesn't really seem all that put out that it's sons died. In fact it seems more pleased that they were able to do things honorably.